Sometimes people make sacrifices that won’t benefit themselves, or even their own generations, but generations yet to be born. They do it at sometimes a heartbreaking price — loss of life, health, livelihood. And even though they may never know the outcome of their sacrifice, they do it anyway. Because it’s the right thing to do.

But even so, it’s hard, especially when the same population is called to make the same sacrifices without any tangible benefit.

The emergency federal regulations on recreational fishing, as well as the commercial fishing industries, essentially eliminating cod and shrimp, and limits to the taking of other species, is yet another blow to an iconic industry that has been hard hit as certain species collapse in the Gulf of Maine.

Why is it happening? Overfishing, sea temperature changes, and new predators that have not been seen in such huge numbers in the past. We’re beginning to see species in the Gulf of Maine that until recently made their home in Chesapeake Bay; eventually, things will settle out to a “new normal” that includes sea bass and blue crab.

But none of this will happen in time to save the commercial fishermen who have shrimp trawlers or groundfish boats.

The loss of the cod fishery, especially, is a bitter pill to swallow, because cod and haddock live together. While the cod season has been virtually eliminated, haddock intake has been bumped up to compensate. But what that means is that any cod that’s scooped up with the haddock will be tossed overboard, likely already dead. Fishermen have voluntarily cut way back on cod catches for decades, because the federal government said that the collapse of the species in the early 90s was due to overfishing in the 70s and 80s. No doubt it was.

But the fish did not return to their normal healthy stocks, and overfishing isn’t the reason anymore.

The catch in the mid-1980s reached 25,000 tons. Strict regulations haven’t allowed the stock to recover; indeed, things are getting worse.

The reason, say National Oceanic and Atmospheric Administration scientists, is that the Gulf of Maine’s waters are warming faster than any other ocean water on Earth. The Gulf has been at least two degrees warmer than its historical 50-degree average in each of the last five years, and in 2012, it measured four degrees higher. On average, it is now warming at a rate of one degree every two years, while in the past, the rate was one degree every 21 years.

Fish are moving to cooler waters, where the water has more nutrients in it. Maine’s Department of Marine Resources says that the cod appear to be moving north and east. The same is true of shrimp, and the great fear is that lobster will be next. Lobsters in Maine are beginning to be found with shell disease, a consequence of warm water, which, while it doesn’t kill them, makes them less attractive and therefore, less valuable. It also slows their reproduction. Farther south, the infection has caused the collapse of lobster stocks.

Maine lobsters aren’t in danger yet. In fact, the lobster fishery has skyrocketed over the last few years. But the unusually warm water in 2012 caused an epidemic of shell disease, and if the water temperatures increase again, it will likely happen again.

In the long run, Maine has to be prepared for changes to its fisheries and be more proactive with helping fishing families make the transitions they must make in order to survive. It is yet another sacrifice asked of a hard-working people, but this one, it can be hoped, will benefit them.